Competition

Question 1

Competition is only found

Answer 1

between species of overlapping niches

Question 2

Degree of niche overlap impacts degree of

Answer 2

competition

Question 3

Complete Competitors

Answer 3

Share the same niche. Limited by the same one resource

Question 4

Competitive Exclusion Principle

Answer 4

Complete competitors cannot coexist indefinitely

Question 5

Liebig’s law of the minimum

Answer 5

population increases until the supply of the most limiting resource prevents it from increasing further.

Question 6

True or false. All competitors cannot coexist.

Answer 6

False. Complete competitors cannot co exist because theyre limited by the same resources. Competitors can if they arent limited by resources.

Question 7

We need to extend the … model to consider the impact of each species on the other

Answer 7

logistic

Question 8

Lotka Voltera Competition Model

Answer 8

Species 1: dN/dt =r1n1(1-N1+aN2/K1)

Species 2: dN/dt=r2n2(1-N2+BN2/K2)

Question 9

a in the Lotka Voltera Competition Model

Answer 9

Competitive effect of species 2 on species 1.

-Species 1/Species 2

Question 10

B in the Lotka Voltera Competition Model

Answer 10

Competitive effect of species 1 on species 2

-Species 2/Species 1

Question 11

Two Species Equilibrium

Answer 11

When the observed growth of both species is 0

Question 12

When species 1 is at equilibrium, the equation is

Answer 12

N1=K1-aN2

Question 13

When N1 =0 then

Answer 13

Either:

N2=K1/a
or
N2=K2

Question 14

When N2=0 then

Answer 14

N1=K1
or
N1=K2/B

Question 15

Species 1 is on … and has … vectors

Answer 15

x axis, horizontal

Question 16

Species 2 is on … and has … vectors

Answer 16

y axis, vertical

Question 17

Phase Plane Diagram

Answer 17

Put species 1 and species 2 on one graph. Four possible outcomes

Question 18

If isocline for species 1 is farther out …

Answer 18

species 2 will go extinct

Question 19

Is isocline for species 2 is farther out…

Answer 19

species 1 will go extinct

Question 20

There is an unstable equilibrium (two possible final equilibrium points) when

Answer 20

K1 and K2 are the outer most parts. B and a are both high.

Question 21

There is a stable equilibrium (coexistence) when

Answer 21

K1 and K2 are the inner most parts.

Question 22

Coexistence can occur when intraspecific competition is

Answer 22

stronger than interspecific competiton. (B and a <1)

Question 23

Two types of true competition

Answer 23

Exploitation and Interference Competition

Question 24

Exploitation Competition

Answer 24

Individuals most efficiently consume the resource. This can drive down resource abundance so that others can persist.

Question 25

Interference Competition

Answer 25

One species actively prevents the other, by behavioral or chemical interference, from exploiting the resource.

Question 26

Allelo-chemicals/Allelopathy

Answer 26

Secondary compounds produced by some plant species that kill neighbors.

Question 27

Apparent competition

Answer 27

Impacts resembling competition but not due to shared resources. Mediated by a shared predator or parasite. Ex. Indirect negative impact of pheasants on partridges via nematodes.

Question 28

The starting point in lotka voleta is

Answer 28

pop of species 1, pop of species 2

Question 29

Cyclic oscillations

Answer 29

Regular oscillations over a period of time. Fluctuations can occur synchronously among populations and species

Question 30

Delays related to ... are common in nature

Answer 30

gestation

Question 31

Delayed Density Dependence

Answer 31

When dependence occurs based on density some point in the past.

Question 32

Degree of cycling in populations depends on r*...

Answer 32

t. Time delay.

Question 33

Larger t (time delay) means

Answer 33

bigger overshoot of K later on

Question 34

When rt is smaller than 0.37...

Answer 34

the population approaches K without oscillations

Question 35

When rt is in the middle of 0.37 and 1.57

Answer 35

There are damped oscillations. Amplitude declines over time.

Question 36

When rt is greater than 1.57

Answer 36

Oscillations. Big time delay

Question 37

Delayed density dependence can also be caused by (other than gestation)

Answer 37

energy/nutrient storage

Question 38

Peak density is reach once every ... years

Answer 38

r*t

Question 39

Smaller populations ... quicker but also ... quicker

Answer 39

grow, go extinct

Question 40

Deterministic model

Answer 40

Used fixed values (ignoring random variation)

Question 41

Stochastic model

Answer 41

Incorporate random variation in population growth rates

Question 42

Demographic Stochasticity

Answer 42

Births and deaths happen in integers. Random differences among individuals cause population rates to vary from the expected mean. Impact important for small populations

Question 43

Environmental Stochasticity

Answer 43

Variation in birth & death rates due to random environmental changes.

Question 44

Impact of environmental and demographic stochasticity more important for ... populations

Answer 44

smaller